The present invention relates to simulated roadway units of the type wherein an endless belt forming the simulated roadway surface is looped around a pair of rotary drums. More particularly, the present invention relates to the stabilization of the belt in response to forces acting laterally in the plane of the upper surface of the belt.
In simulated roadway units employed generally for tire testing the tire or tires are in rotary contact with the upper portion of the belt which may drive the tires or be driven by the tires. In other words, the belt may be passive or active. The combination of forces imparted to the belt produce an unusually large lateral force component which, if uncorrected, can cause the belt to drift off the drums. It is therefore essential than an efficient, simple and inexpensive stabilizing mechanism be provided to counterbalance and correct such lateral force components.
Generally, various apparatus have been suggested for stabilizing endless belts mounted on drums, these are typified by U.S. Pat. Nos. 3,635,475; 2,484,473; and 994,910 which, respectively, relate to a fluid servo control system; an electric motor servo control system; and a gear train control system. These systems are complex, costly and consist of a relatively large number of moving parts each of which are subject to defects or failure.